This invention relates to electric motors and methods of making machine drives utilizing such motors and has been devised particularly though not solely, for, making motors for use as a source of power and/or drive, for a laundry machine.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide an electric motor and/or a machine drive utilizing such a motor a method of making the same.
Accordingly in one aspect the invention consists in a method of manufacturing a motor element of an electric motor the motor element being selected from a rotor having a ferromagnetic circuit spaced radially from a shaft carrier mounting means and a stator having a ferromagnetic circuit including a set of poles adapted to receive electrical windings thereon, the poles being spaced radially from a shaft carrier mounting means thereof the comprising the steps of fixing the selected ferromagnetic circuit in a plastics injection moulding die, the die having walls defining a cavity to receive injection molded plastics material, the walls including wall portions to define a part of the cavity into which plastics material is injected to form the appropriate selected shaft carrier mounting means and injecting a plastics material into the die; to provide a plastics molding having embedded therein the ferromagnetic circuit; to form the shaft carrier mounting means and to form a web between the ferromagnagnetic circuit and the shaft carrier mounting means the die holding desired parts of the ferromagnetic circuit in a fixed radial disposition relative to the shaft carrier mounting means to maintain substantial concentricity between the desired parts of the ferromagnetic circuit and the shaft carrier mounting means.
In a further aspect the invention consists in a method of manufacturing an electric motor comprising the steps of taking a motor element comprising a stator made by a method according to the preceding paragraph, placing electrical windings on the poles thereof and taking a further motor element comprising a rotor made according to the preceding paragraph, magnetizing part of the ferromagnetic circuit to a permanent magnet state, attaching the stator to a bearing housing containing a distal bearing separated from a proximal bearing, the outer surface of the proximal bearing being mounted partly in the shaft carrier mounting, mounting a shaft in the bearings and mounting the rotor when the shaft so that on the windings on the stator are energized through an electronic commutation circuit, the rotor is caused to rotate.
In a further aspect the invention consists in a motor element of an electric motor selected from a rotor having a ferromagnetic circuit spaced radially from a shaft carrier mounting means thereof and a stator having a ferromagnetic circuit including a set of poles adapted to receive electrical windings thereon the poles being spaced radially from a shaft carrier mounting means thereof the motor element comprising a plastics injection molding having embedded therein parts of the ferromagnetic circuit and having a web connecting the ferromagnetic circuit to the shaft carrier mounting means with parts of the ferromagnetic circuit held in a fixed radial disposition relative to the shaft carrier mounting means to maintain substantial concentricity between the desired parts of the ferromagnetic circuit and the shaft carrier mounting means.
In a still further aspect the invention consists in an electric motor comprising a motor element comprising a stator according to the preceding paragraph, the stator having electrical windings on the poles thereof and further motor elements comprising a rotor made according to the preceding paragraph, the motor having some of the ferromagnetic circuit magnetized to a permanent magnet state, a bearing housing attached to the stator, the housing containing a distal bearing separated from a proximal bearing, the outer surface of the proximal bearing being mounted partly in the bearing housing and partly in the shaft carrier mounting, a shaft in the bearings and the rotor being mounted on the shaft so that when windings on the poles of the stator are energized through an electronic commutating circuit magnetic coupling occurs to cause the rotor to rotate.
In a still further aspect the invention consists in a method for manufacturings a motor for a laundry machine having an outer casing, a water container within the casing, a spin tub rotatable within the container, an agitator mounted for agitation within the spin tub, the agitator being operable to enable the agitator alone to be agitated backwards and forwards or the spin tub and the the agitator to be rotated in a single and spinning speed, the agitator being driven by an electric motor according to the preceding paragraph, the shaft driving the agitator and the bearing housing being fixed to a lower part of the container.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.